Writer: Kay Ledbetter

Producers will need to pick up a second round of auxin training this year if they plan to use dicamba products, according to a Texas A&M AgriLife Extension Service specialist.

In late October, the U.S. Environmental Protection Agency announced it will extend the registration of dicamba for two years for over-the-top weed control in dicamba-tolerant cotton and soybean.

The extended labels include changes to ensure these products continue to be used effectively and to address concerns about off-target movement, said Scott Nolte, Texas A&M AgriLife Extension Service state weed specialist, College Station.

tractor spraying cotton field
Producers using auxin herbicides face new training requirements.

Initial label changes state only certified applicators may apply dicamba over the top of the crop, Nolte said. The changes also prohibit over-the-top applications 60 days after planting for cotton and 45 days for soybeans.

The new rules limit the number of over-the-top applications to two for both cotton and soybeans, and limit applications between one hour after sunrise and two hours before sunset. In counties where endangered species exist, applicators must maintain the downwind 110-foot buffer and add a 57-foot buffer around the other sides of the target field.  

Nolte warned some of these new changes may be different before the 2019 spring growing season pending 24C, additional-use, requests submitted to the Texas Department of Agriculture. If approved, the 24C labels will be available on the TDA website, www.texasagriculture.gov/RegulatoryPrograms/Pesticides.

Three dicamba products – Engenia herbicide by BASF Corporation, XtendiMax herbicide with VaporGrip Technology by Bayer CropScience, and DuPont FeXapan herbicide Plus VaporGrip Technology by Corteva Agriscience – are restricted-use pesticides and state-limited-use pesticides in Texas, which requires the sale to and use by certified applicators only.  

Nolte clarified that the auxin trainings are not a substitute for the state-specified certified applicator training, which is required to purchase and use restricted-use pesticides.

Also, TDA has added 2,4-D choline formulations – Enlist Duo and Enlist One for use on 2,4-D-tolerant crops – to be included in these mandatory trainings. These are state-limited-use pesticides in Texas and can only be sold to and used by certified applicators or those working under the supervision of a certified applicator.

The two-hour mandated auxin trainings for the new year will include the following topics: why do auxin herbicides require additional precautions, label requirements for approved auxin formulations, understanding temperature inversions, spray system hygiene, record keeping and using dicamba or 2,4-D in a weed management system.  

AgriLife Extension will be providing a two-hour in-person course, approved by TDA, that will fulfill the training requirements for dicamba and 2,4-D choline products and will include two continuing education units for laws and regulations.

Contact the local AgriLife Extension county agent for training locations, dates and times.

Nolte said BASF Corporation, Bayer CropScience and Corteva Agriscience also will be requesting TDA-approved training courses focusing on each company’s specific technology and will therefore only be one-hour, one CEU courses.